title: Influence of hydroxyapatite particle size on bone cell activities: an in vitro study.
abstract: Over the past decade, a large number of biomaterials have been proposed as artificial bone fillers for repairing bone defects. The material most widely used in clinical medicine is hydroxyapatite. The aim of our investigation was to study the effect of hydroxyapatite size mechanism on osteoblasts. The osteoblasts were cultured in vitro with 0.1% (1 mg/mL) of various sized hydroxyapatite particles (0.5-3.0, 37-63, 177-250, and 420-841 microm) for 1 h, 3 h, 1 day, 3 days, and 7 days. The results showed that adding hydroxyapatite particles to osteoblast cultures can significantly affect osteoblast cell count. Osteoblast populations decreased significantly. Osteoblast mean surface areas also changed significantly. Transforming growth factor-beta1 (TGF-beta1) concentrations in culture medium decreased significantly with the addition of hydroxyapatite particles. Prostaglandin E2 (PGE2) concentrations in medium increased significantly. The changes in TGF-beta1 and PGE2 concentration were more significant and persisted longer in smaller-particle groups. The inhibitory effects of hydroxyapatite particles on osteoblast cell cultures were mediated by the increased synthesis of PGE2. Caution should be exercised before using a hydroxyapatite product which could easily break down into fine particles.
authors.affiliation: Department of Orthopedic Surgery, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, ROC.
authors.forename: J S
authors.initials: JS
authors.lastname: Sun
authors.forename: H C
authors.initials: HC
authors.lastname: Liu
authors.forename: W H
authors.initials: WH
authors.lastname: Chang
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: F H
authors.initials: FH
authors.lastname: Lin
authors.forename: H C
authors.initials: HC
authors.lastname: Tai
mesh_terms: D000469:Alkaline Phosphatase; D000818:Animals; D000831:Animals, Newborn; D001672:Biocompatible Materials; D001842:Bone and Bones / Q000166:cytology*; D002452:Cell Count; D002467:Cell Nucleus / Q000648:ultrastructure; D002478:Cells, Cultured; D003470:Culture Media; D015232:Dinoprostone / Q000494:pharmacology; D006882:Hydroxyapatites; D010006:Osteoblasts / Q000187:drug effects / Q000648:ultrastructure; D010316:Particle Size; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000494:pharmacology
chemical_list: D001672:Biocompatible Materials; D003470:Culture Media; D006882:Hydroxyapatites; D016212:Transforming Growth Factor beta; D000469:Alkaline Phosphatase; D015232:Dinoprostone